uction in the several branches of industry has been given by Mr.
D.A. Wells, who regards machinery as the direct cause of depressed
trade, operating in three ways--(1) increased capacity of production,
(2) improved methods of distribution, (3) the opening up of new
abundant supplies of raw material. Thus production grows faster than
consumption. "In this way only is it possible to account for the
circumstances that the supply of the great articles and
instrumentalities of the world's use and commerce have increased
during the last twelve or fifteen years in a far greater ratio than
the contemporaneous increase of the world's population or of its
immediate consuming capacity."[150]

The earlier inventions in the textile industries, and the general
application of steam to manufacture and to the transport services,
have played the most dramatic part in the industrial revolution of the
last hundred years. But it should be borne in mind that it is far from
being true that the great forces of invention have spent themselves,
and that we have come to an era of small increments in the growth of
productive power. On the contrary, within this last generation a
number of discoveries have taken place in almost all the chief
industrial arts, in the opening up of new supplies of raw material,
and in the improvement of industrial organisation, which have
registered enormous advances of productive power. In the United
States, where the advance has been most marked, it is estimated that
in the fifteen or twenty years preceding 1886 the gain of machinery,
as measured by "displacement of the muscular labour," amounts to more
than one-third, taking the aggregate of manufactures into account. In
many manufactures the introduction of steam-driven machinery and the
factory system belongs to this generation. The substitution of
machinery for hand labour in boot-making signifies a gain of 80 per
cent. for some classes of goods, 50 per cent. for others. In the silk
manufacture there has been a gain of 50 per cent., in furniture some
30 per cent., while in many minor processes, such as wood-planing, tin
cans, wall-papers, soap, patent leather, etc., the improvement of
mechanical productiveness per labourer is measured as a rise of from
50 to 300 per cent. or more. The gain is, however, by no means
confined to an extension of "power" into processes formerly performed
by human muscle and skill. Still more significant is the increased
mechanical ef